This invention relates to cable drums and is also concerned with methods of, and apparatus for, using the drums for laying submarine cable.
When barges or similar vessels are used for submarine cable laying, the weight of a loaded drum (i.e. a drum wound with cable), which is about 30-35 tons, demands the use of a large (e.g. 50 ton) crane to lower the drum on to the barge, whereby it can rotate about a substantially horizontal axis, supported by trunnions. The drum is penetrated from end to end by a central hole which is used to locate a spindle about which the drum can rotate freely.
The crane is large and expensive and its use is therefore uneconomic, particularly as the laying barge has to return frequently for replacement of the drum.